1. Field of the Invention
The present invention relates to a dust cover assembly mounted on a shock absorber constituting a vehicular suspension mechanism, and a manufacturing method of the dust cover assembly.
2. Description of the Related Art
From the past, with the object of preventing foreign matter such as rain, dust or the like from penetrating the sliding part of a piston rod, a dust cover that encloses around the piston rod is mounted on the shock absorber constituting the suspension mechanism of a vehicle such as an automobile or the like. Also, to prevent damage or impact due to excessive contraction of the shock absorber when there is excessive external input to the suspension mechanism, a bound stopper formed with an elastic body is externally inserted on the piston rod.
However, as a structure for assembling both the dust cover and the bound stopper to the shock absorber, it is also possible to apply an integrally molded article of the dust cover and the bound stopper as disclosed in Japanese Unexamined Patent Publication No. JP-A-2001-3973. However, the dust cover and the bound stopper have different required characteristics, so when using the integrally molded article, there is the problem that it is not possible to select respectively suitable materials.
In light of that, in many cases, a respectively separately formed dust cover and bound stopper are used. Also, the separately formed dust cover and bound stopper, as described in U.S. Pat. No. 6,648,110 for example, can be assembled on an upper support for attaching the shock absorber piston rod to the vehicle body. In specific terms, with the outer metal fitting of the upper support fixed to the vehicle body being a cup shaped press formed article, while the bound stopper is fit and held on the peripheral wall inner surface of this outer metal fitting, the dust cover is blow molded and simultaneously externally fit and fixed to the peripheral wall outer surface of the outer metal fitting.
However, with this kind of prior art assembly structure, the externally fit and fixed part of the dust cover to the outer metal fitting is exposed to the outside, so there was the risk of damage occurring due to splashing of stones or the like while the vehicle is traveling and having the dust cover fall off. Also, when it is difficult to use a round cylinder shaped outer circumferential surface with the outer metal fitting, there was the problem that it was not possible to even do external fitting and fixing of the dust cover in the first place.